- 问题详情:Recently,asolarpowered(太阳能动力的)planetooktotheskyforthefirsttime.Ithadpassedanimportanttestonthewaytotravelaroundtheworld.TheplanetookofffromanairportinSwitzerland(瑞士)at45kmanhour.Itslowlyroseabovethefieldsandintothesky.“Therehasneverbeenan...
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